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All the ideas for 'What is Logic?st1=Ian Hacking', 'Philosophy of Language' and 'reports of last days'

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29 ideas

1. Philosophy / D. Nature of Philosophy / 2. Invocation to Philosophy
The unexamined life is not worth living for men [Socrates]
2. Reason / D. Definition / 3. Types of Definition
A decent modern definition should always imply a semantics [Hacking]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / d. Basic theorems of PL
Gentzen's Cut Rule (or transitivity of deduction) is 'If A |- B and B |- C, then A |- C' [Hacking]
Only Cut reduces complexity, so logic is constructive without it, and it can be dispensed with [Hacking]
'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking]
4. Formal Logic / D. Modal Logic ML / 1. Modal Logic
The interest of quantified modal logic is its metaphysical necessity and essentialism [Soames]
5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
The various logics are abstractions made from terms like 'if...then' in English [Hacking]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
First-order logic is the strongest complete compact theory with Löwenheim-Skolem [Hacking]
A limitation of first-order logic is that it cannot handle branching quantifiers [Hacking]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Second-order completeness seems to need intensional entities and possible worlds [Hacking]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
With a pure notion of truth and consequence, the meanings of connectives are fixed syntactically [Hacking]
5. Theory of Logic / E. Structures of Logic / 4. Variables in Logic
Perhaps variables could be dispensed with, by arrows joining places in the scope of quantifiers [Hacking]
5. Theory of Logic / F. Referring in Logic / 2. Descriptions / a. Descriptions
Indefinite descriptions are quantificational in subject position, but not in predicate position [Soames]
5. Theory of Logic / F. Referring in Logic / 2. Descriptions / c. Theory of definite descriptions
Recognising the definite description 'the man' as a quantifier phrase, not a singular term, is a real insight [Soames]
5. Theory of Logic / G. Quantification / 7. Unorthodox Quantification
The universal and existential quantifiers were chosen to suit mathematics [Soames]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
If it is a logic, the Löwenheim-Skolem theorem holds for it [Hacking]
10. Modality / A. Necessity / 5. Metaphysical Necessity
We understand metaphysical necessity intuitively, from ordinary life [Soames]
There are more metaphysically than logically necessary truths [Soames]
19. Language / A. Nature of Meaning / 4. Meaning as Truth-Conditions
To study meaning, study truth conditions, on the basis of syntax, and representation by the parts [Soames]
Tarski's account of truth-conditions is too weak to determine meanings [Soames]
19. Language / D. Propositions / 4. Mental Propositions
We should use cognitive states to explain representational propositions, not vice versa [Soames]
22. Metaethics / B. Value / 2. Values / e. Death
If death is like a night of dreamless sleep, such nights are very pleasant [Socrates]
Men fear death as a great evil when it may be a great blessing [Socrates]
23. Ethics / B. Contract Ethics / 8. Contract Strategies
We should not even harm someone who harms us [Socrates]
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / c. Motivation for virtue
A good man cannot be harmed, either in life or in death [Socrates]
23. Ethics / C. Virtue Theory / 3. Virtues / c. Justice
One ought not to return a wrong or injury to any person, whatever the provocation [Socrates]
23. Ethics / C. Virtue Theory / 4. External Goods / c. Wealth
Wealth is good if it is accompanied by virtue [Socrates]
25. Social Practice / D. Justice / 2. The Law / a. Legal system
Will I stand up against the law, simply because I have been unjustly judged? [Socrates]
28. God / C. Attitudes to God / 5. Atheism
Socrates is accused of denying the gods, saying sun is stone and moon is earth [Socrates, by Plato]